Vidor Gencel
Verified Expert in Engineering
Blockchain Developer
Belgrade, Serbia
Toptal member since April 30, 2018
Vidor is a Computer Science Ph.D. candidate actively doing research and development in the blockchain space with a focus on Tendermint, Ethereum, and Hyperledger. He has been involved in software development since a young age and has participated in the development of different software solutions for microprocessors, core banking, the web, and money-handling equipment. Vidor has strong business English and years of remote-working experience.
Portfolio
Experience
- PHP - 9 years
- JavaScript - 8 years
- Node.js - 5 years
- Cryptography - 4 years
- Blockchain - 4 years
- Ethereum - 3 years
- Solidity - 3 years
- Tendermint - 2 years
Availability
Preferred Environment
Slack, Git, Visual Studio Code (VS Code), MacOS
The most amazing...
...thing I've done is discover critical security vulnerabilities in Ethereum smart contracts that could have produced great financial loss.
Work Experience
Founder | Blockchain Architect
VGNG LTD
- Led development process end-to-end, from proposal development to requirements engineering, architecture, development, and delivery.
- Defined product development guidelines for cryptocurrency wallets, claim issuance, and aggregation/selective disclosure using advanced cryptographic techniques.
- Technically vetted and managed a team of 10 engineers and designers.
- Architected and led the development of an advanced verifiable claim processing system to optimize fundraising processes on crypto exchanges by aggregation and selective disclosure of cryptographic claims.
- Architected solutions based on Tendermint and Cosmos SDK.
- Architected and participated in the development of a Quorum based blockchain used to manage reward points. Apart from the core blockchain and smart contract development, the system included a web wallet interface, an administration panel, a blockchain explorer, and a system monitoring dashboard.
- Architected and participated in the development of a dashboard that aggregates blockchain data and displays proof of stake related economic metrics.
Blockchain Developer
Freelance Work
- Developed secure Solidity smart contracts for the Ethereum blockchain.
- Conducted security audits of Solidity smart contracts.
- Implemented interaction with Ethereum smart contracts using JavaScript and web3.
- Created ICO smart contracts.
- Acted as token economics consultant.
Blockchain Architect | VP Engineering
Under NDA
- Researched and implemented bleeding-edge blockchain technology including core blockchain development, network component development and development of revolving blockchain integrations.
- Architected and led development of a blockchain platform based on Tendermint and Cosmos SDK with native KYC/AML support to be used in government applications.
- Participated in the process of drafting a standard for an Inter Blockchain Communication protocol.
- Conducted technical interviews and managed a remote team of 5-10 people and coordinated communication with other teams.
- Interacted with multiple stakeholders in the process of analysing and defining business use cases.
CTO | Blockchain Engineer
Grayblock
- Analyzed the user requirements and researched the electric power generation industry.
- Consulted regarding blockchain choice and business tokenization.
- Created a proof of concept in record breaking time.
- Created a detailed estimate of blockchain transaction costs.
- Researched, proposed and integrated several Ethereum Improvement Proposals (EIPs).
- Developed backend services that mimic real world infrastructure.
- Developed an fully functional decentralized application (DApp) with React.js frontend communicating with the Ethereum blockchain.
- Implemented various transaction cost optimizations utilizing game theory principles.
- Deployed a private PoA blockchain for closed beta testing.
CTO | Blockchain Engineer
Best Millions
- Coordinated development and developed a blockchain-backed international lottery platform infrastructure.
- Conducted technical interviews and formed the technical development team.
- Transformed user requirements into technical specifications and delegated development tasks.
- Researched and developed efficient off-chain data storage and querying infrastructure with on-chain proofs.
- Developed secure Ethereum smart contracts in Solidity with accompanying tests.
Blockchain Engineer
Under NDA
- Researched Ethereum scaling solutions including payment channels and state channels with underlying theory of Conflict-free replicated data types (CRDTs).
- Analyzed whitepapers describing different payment and state channel proposals.
- Gathered requirements and analyzed trade-offs for different scaling solution proposals.
- Improved an existing Layer 2 blockchain scaling protocol.
- Worked on implementing a solution that optimizes existing payment channel implementations for low availability clients.
Blockchain Developer
Messly
- Provided a comparative analysis of different blockchain technologies to be used on the project.
- Consulted regarding the choice of blockchain and technology stack and presenting trade-offs.
- Analyzed and implemented user requirements for medical business processes.
- Deployed a Hyperledger Indy blockchain and implemented business logic for self-sovereign identity.
- Reverse engineered Hyperledger Indy protocols and developed a proof of concept on top of Hyperledger Fabric and Hyperledger Composer.
- Developed and deployed business networks with multiple participants built on top of Hyperledger Fabric with Hyperledger Composer.
- Created maintenance scripts for analyzing and upgrading business networks.
- Developed Docker deployment scripts for blockchain business networks.
- Built and deployed a "blockchain bridge" that connects different blockchains and enables cross-chain integrations.
- Developed and deployed Ethereum smart contracts including customized ERC-20 tokens.
Software Engineer
stam.io
- Designed architecture and developed a fast, reliable and scalable REST API for a cloud based recruitment and workforce management platform.
- Introduced advanced resource planning features that take into consideration employee availability and a flexible platform for generating and maintaining user shifts.
- Implemented tests, deployment scripts and maintained development, staging and production environments.
- Developed scripts for live monitoring and reporting of different environments.
- Performance enhancement with query optimization and caching.
- Coordinated task development for backend features with other developers.
- Conducted technical interviews with internship candidates.
- Implemented web application features in React.js.
Student Assistant
School of Electrical Engineering
- Wrote semester development project proposals.
- Mentored and consulted students regarding game development projects.
- Assisted students during lab exercises in computer laboratories.
- Tested students knowledge and graded their work.
- Participated as a student assistant within several programming related and operating system related subjects.
Software Engineering Intern
Asseco-see
- Implemented declarative workflow automation features for core banking software platform.
- Researched the Windows Server Service Bus and Workflow Manager platform and the way it has been embedded in the Microsoft Sharepoint Portal.
- Sett up Proof of Concept VM environments for Workflow Manager, Service Bus and SharePoint.
- Developed PoC proxy event analyzer of arbitrary Service Bus messages relayed to Workflow Manager.
- Built metadata export/publishing command line tools used to move workflow definitions between different environments.
- Created custom declarative activities that wrap calls to REST APIs.
- Developed PoC sample workflow that uses mix of built-in and custom developed activities to orchestrate a sample scenario.
Owner
Mikro Hosting
- Piloted a one-man web hosting and domain registration service business.
- Developed a web hosting account management and domain registration automatization software in PHP and MySQL. The system included a ticketing support center for customers.
- Set up and maintained a Linux server including WHM, cPanel, PHP, Apache, backups, and more.
- Provided customer support.
- Contributed to financial planning.
Experience
Custom Proof of Work Blockchain
Chatbot Hackathon 1st Place
My team built an advanced chat bot which was announced as the best technical solution as well as best presented bot. The bot was build using various NLP techniques using Java and Node.js, to understand the question asked, and external APIs to provide a competent answer.
Reminder Chatbot
The bot was developed in Java using the Stanford NLP library. The database used was MongoDB.
The paper describing the process was published on the Telecommunications Forum (TELFOR) with the title "A software agent for social networks using natural language processing techniques"
IOPlac - Money Handling Kiosk
TrippyTap - Mobile Game
XBoost
Education
Progress towards a Ph.D. in Software Engineering
School of Electrical Engineering, University of Belgrade - Belgrade, Serbia
Master's Degree in Software Engineering
School of Electrical Engineering, University of Belgrade - Belgrade, Serbia
Bachelor's Degree in Software Engineering
School of Electrical Engineering, University of Belgrade - Belgrade, Serbia
Skills
Libraries/APIs
Web3.js, Node.js, REST APIs, jQuery, Socket.IO, React
Tools
Git, Hyperledger Indy, BTC Wallet, Docker Compose, Slack, MQTT, WebStorm, PhpStorm
Languages
SQL, PHP, HTML, JavaScript, Solidity, Go, Java, C, C++, C#, TypeScript, Bash, CSS
Frameworks
Truffle, Laravel, Express.js, Tendermint, Cosmos SDK, Windows Workflow Foundation, Redux
Platforms
Blockchain, Ethereum, Blockchain Platforms, Hyperledger Composer, Linux, Docker, Hyperledger Fabric, MacOS, Hyperledger, Amazon Web Services (AWS), Visual Studio Code (VS Code)
Storage
MySQL, BigchainDB, Redis, Memcached, MongoDB
Paradigms
Concurrent Programming, Parallel Programming, REST, Microservices
Other
Elliptic Curve Cryptography, Public-key Cryptography, DApps, Smart Contracts, Cryptocurrency, Distributed Ledgers, Cryptocurrency APIs, Ethereum Smart Contracts, Customized Blockchains, Blockchain Architecture, Solution Architecture, HD Wallets, Quorum, Scaling, Cryptographic Protocols, Applied Cryptography, Cryptography, Bitcoin, IPFS, ERC-827, ICO, Distributed Systems, Chatbots, Cryptocurrency Wallets, Cryptocurrency Development, Data Structures, Algorithms, Mobile Wallet, IEO, Web 3.0, Oracle Service Bus (OSB), Workflow, ERC-20, ERC-721, WebSockets, Ark.io
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